Electric heater panel contact structure



Nov. 18, 1958 E D. KNOLL 2,861,168

ELECTRIC HEATER PANEL. CONTACT STRUCTURE Filed May 14, 1957 n 2,861,168 l Patented Nov. 18, 1958 ELECTRIC HEATER PANEL CONTACT STRUCTURE David Knoll, Bayside, N. Y., assigvnor to Berko Electric Manufacturing Corporation, Queens Village, N. Y., a corporation of New York l Application May 14, 1957, Serial No. 659,054

6 Claims. (Cl. 219-34) This invention relates to electric heaters and more speciiically to a novel and improved eontactor particularly useful for electric glass panelheaters.

In the manufacture of electric heaters wherein pressure contact is made with the heating element to supply electric energythereto, it is diiiicult to maintain a low contact resistance in cases where limited space is available. This is particularly the case with high wattage glass panel heaters which have presented dicult and costly design and construction problems in order to secure reasonable heater life.

This invention overcomes the foregoing diiiiculty in the manufacture of panel type heaters utilizing pressure type contacts and aifords an improved contact structure characterized by its effectiveness, low cost, compactness and dependability.

'Another object of the invention is the provision of a novel and improved electrical pressure-type contact assembly that may be simply and easily manufactured and at the same time provide a contact assembly wherein the pressure of the contacts on the panel will be substantially uniform.

Still another object of the invention resides in the provision of a novel and improved electrical contact assembly for electric heaters.

The above and other objects and advantages of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

In the drawings:

Fig. 1 is a perspective view of a contact assembly in accordance with the invention;

Fig. 2 is a cross sectional view of an electric panel heater embodying the invention and is taken along the line 2 2 of Fig. 3;

Fig. 3 is a fragmentary view of a panel heater in partial section and is taken along the line 3-3 of Fig. 2; and

Fig. 4 is an enlarged cross sectional view of the contact structure of Figs. 1 and 2 showing its cooperation with a glass heating panel.

Panel type electric heaters and particularly those em ploying glass'panels often utilize a panel having a conductive coating on one surface and silver contacting strips parallel to and spaced from at least two opposing edges for feeding electric current to the panel. It is desirable in heaters of this character to maintain the thickness of the heater assembly at a minimum and in high Wattage heaters using long narrow panels it is especially important to distribute the current as uniformly as possible along each strip to avoid damage by the introduction of excessive current at one or more points. With this invention a relatively large number of contact points can be provided within a relatively short span with substantially uniform pressure applied between each contact and the cooperating silver conducting strip.

Referring now to the drawings illustrating one embodiment of the invention, the contact assembly includes a member 11 formed of resilient material having two bowed sections 12 and 12. The central portion 13 of the assembly is substantially flat and in the illustrated embodiment has a pair of openings 14 for attachment l of the strip to a supporting member'. The outer ends 15 and 16 of the bowed sections 12 and 12 are preferably curved as illustrated so that they will slide 'freely on the surface of the contact supporting structure.

Each of the bowed members 12 and 12 carries an elongated strip of conducting material 17 that is generally U-shaped in section and is secured to the crest of the associated bow by a single rivet 18 or other suitable fastening means. Each member 17 has an internal width that will accommodate its cooperating bow and thereby v maintain the channel members in alignment one with the other. Each channel member further includes a pair of carbon button contacts 19 that may be riveted or othery I of Fig. 1 with a glass heating panelV and 'for simplicity only a fragmentary portion of a glass panel heaterV has been illustrated. In this heater the conductive glass panel is generally denoted by the numeral 20 and is supported by four corner insulating blocks 21 carried by an appropriate protective frame 22. Within the frame 22 there is provided in the instant embodiment of the invention a reflecting member 23 which usually is slightly larger in area than the glass panel 20. This frame carries a pair of spaced parallel strips of insulating material 24 in alignment with the silver conducting strips 25 carried by the glass panel 20. Overlying each insulating strip 24 is a strip of conducting material 26 which supports the contact assembly 10 and in addition feeds electrical energy thereto. rivets 27 which pass through the openings 14 of the contact assembly 10 and through the strips 26 and 24.

The depth of the bows 11 and 12 previously described is coordinated with the distance between the reflector 23 and the glass panel 20 so that when the panel 20 is in place over the contact assembly 10 the bows will be depressed sufficiently to provide the desired pressure between the contactors 19 and the silver strip 25. Inasmuch as each bow carries a pair of contactors on channels 17 the channels can tilt relative to the bows so that each bow will apply substantially uniform pressure to its pair of contacts. Inasmuch as the bows are all formed in a similar manner all of the contactors Will be pressed against the silver strip 25 with substantially the same pressure. It will be observed that when the bows are depressed in the assembly of the heater as illustrated the curved end portions 15 and 16 of the bows will slide relative to the conductive strip 26 so that energy will be fed to the contact assembly through at least three points.

In the construction of electric heaters of the type above described one or more contact assem-blies 10 are generally used in end to end relationship on a single conductive strip 26 in order to provide an electrical contact along one edge of a conducting plate and a similar contact arrangement is used along the opposite edge of the plate. Current is then fed to each of the contact strips 26 in order to energize the heater.

While only one embodiment of the invention has been illustrated and described it is apparent that modications, alterations and changes may be made without departing from the true scope and spirit thereof.

What is claimed is:

1. fIn an electric panel type heater having a conductive panel and electrical connector strips adjacent at least two edges of said panel, pressure connectors for applying energy to said panel and uniformly bearing against said The strip 26 is secured in position by a pair of material carried at the crest of said bow and at least' two.' electrical contacts carried in spaced relationship by the last said member.

2. Apparatus according to claim 1 wherein the last'said' member is channel shaped and the contacts are carried'4 near the ends of said channel.

3. Apparatus according to claim 2 wherein said contacts are carbon buttons having substantially large con? tacting surfaces.

4. A contactor for panel type electricheaters compris,-Y

ing a member of electrically conductive resilient material formed in the shape of a bow, an elongated member of electrically conductive material carried at the crest of said bow and at least two electric contacts carried by said elongated member.

5. A contactor for panel type electric heaters comprising a double-bowed member of electrically conductive resilient material and an elongated member of electrically conductive material carried at the crest of each bow and at least two electric contacts carried by each -of said elongated members.

6. In an electric panel type heater having a conductive panel and electrical connector strips adjoining at least two edges of saidpanel, pressure connectors for applying energy to said panel and uniformly bearing against said strips, each connector comprising a double-bowed mem- =ber of resilient electrically conductive material, means centrally of said member for attachment to a support with the free ends of the bows in slidable contact with said support, an elongated channel shaped member of conductive material carried at the crest of each bow with the legs of each channel member engaging its associated bow to maintain the channel members in alignment one with the other and at least two carbon button contacts carried in spaced relationship by each of said channel members.

References Citedin` the tile of this patent UNITED STATES PATENTS 

